Process for hardening gelatin using particular dihydroxy dioxanes

ABSTRACT

A PROCESS FOR HARDENING GELATIN WHICH COMPRISES REACTING THE GELATIN WITH AT LEAST ONE COMPOUND REPRESENTED BY THE FORMULAE:   5-R1,6-R2-1,4-DIOXANE-2,3-DIOL AND   5,6-(-Z-)-1,4-DIOXANE-2,3-DIOL   WHEREIN R1 REPRESENTS A MEMBER SELECTED FROM THE GROU CONSISTING OF A HYDROGEN ATOM, AN ALKYL GROUP, A HOLOGENSUBSTITUTED ALKYL GROUP, AN ALKOXYALKYL GROUP, AN ARYL GROUP AND AN ARYLOXYALKYL GROUP; R2 REPRESENTS A MEMBER SELECTED FROM THE GROUP CONSISTING OF AN ALKYL GROUP, AN HALOGEN-SUBSTITUTED ALKYL GROUP, AN ALKOXYALKYL GROUP, AN ARYL GROUP AND AN ARYLOXYALKYL GROUP; AND Z REPRESENTS NON-METALLIC ATOMS REQUISITE FOR FORMING A CARBON RING SELECTED FROM THE GROUP CONSISTING OF A SATURATED RING AND AN UNSATURATED RING, WHEREIN SAID RING MAY BE SUBSTITUTED.

United States Patent Oflice Patented June 25, 1974 3,819,608 PROCESS FOR HARDENING GELATIN USING PARTICULAR DIHYDROXY DIOXANES Nobuo Yamamoto, Kameji Nagao, and Ikutaro Horie, Kauagawa, Japan, assignors to Fuji Photo Film Co., Ltd., Kanagawa, Japan No Drawing. Continuation of abandoned application Ser. No. 850,673, Aug. 15, 1969. This application Nov. 24, 1971, Ser. No. 201,999

Claims priority, application Japan, Aug. 17, 1968, 43/58,799 Int. Cl. C09h 7/00 US. Cl. 260-117 15 Claims ABSTRACT OF THE DISCLOSURE A process for hardening gelatin which comprises reacting the gelatin with at least one compound represented by the formulae:

This application is a continuation of application Ser. No. 850,673, filed Aug. 15, 1969, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a process for hardening gelatin.

2. Description of the Prior Art Gelatin is used in the manufacture of various elements of photographic light-sensitive materials, such as silver halide emulsion layers, emulsion-protective layers, filter layers, anti-halation layers, backing layers, subbing layers of a film base or baryta layers of printing paper. Such gelatin-containing photographic light-sensitive materials are often treated with various aqueous solutions which may vary in pH and in temperature. If the gelatin-containing layer has not been treated with a hardener, it will be excessively swollen in an aqueous solution and will become fragile and, in a processing bath at a high temperature, will be completely dissolved therein.

There have hitherto been known numerous compounds which harden gelatin and thereby enhance the water-resistance of gelatin film. Chrome alum and like inorganic compounds, formaldehyde, glyoxal and like aldehydes, and mucochloric acid, 2,3-dihydroxy-1,4-dioxane and aldehyde-like analogues are examples of such compounds and they are well known as hardeners in the manufactureof photographic light-sensitive materials. However, the known hardeners have certain drawbacks. For instance, they exhibit undersirable effects on the properties of a photographic photosensitive material, namely, an increase in fog, a decrease in photographic sensitivity or so called post hardening owing to the slowness of the hardening reaction, a loss of their hardening ability when added with certain photographic additives, or they are satisfactory with respect to enhancement of the water-resistivity of the photographic light-sensitive material but insufficient with respect to improvement of mechanical strength such as scratch-resistivity.

The principal object of the present invention is to provide a novel hardener for gelatin which will afford excellent water-resistivity and scratch-resistivity without any undesirable effects on the properties of the photographic light-sensitive material.

SUMMARY OF THE INVENTION The present invention provides a process for hardening gelatin by reacting the gelatin with a novel compound represented by the formulae:

wherein R represents a hydrogen atom, an alkyl group, a halogen-substituted alkyl group, an alkoxyalkyl group, an aryl group or an aryloxyalkyl group; R represents an alkyl group, a halogen-substituted alkyl group, an alkoxyalkyl group, an aryl group or an aryloxyalkyl group; and Z represents the non-metallic atoms requisite for forming a saturated or unsaturated carbon ring, which may be substituted.

Detailed Description of the Invention Accordingly, in accordance with the present invention, it is possible to enhance both the water-resistivity and the scratch-resistivity of gelatin-containing layers or gelatinmoldings.

The novel hardeners of the present invention will be exemplified by the following compounds. Compound (1) 1120 CHOH CH H-OH 010141 0 Compound (2) O 1120 CHOH CH H-OH CHflCHzM-Cfia \O/ Compound (3) 0 H2C CH-OH CH3(CH2)2'CH2OOHZ II 11-01! Oompound(4) 0 1120 CLEL-OH CH CH--0H C? Compound (5) O 1320 CH-OH 23H H-OH Compound (6) CH (3H Cl (EH-OH CH: CH CH-OH Compound (7) O CH-OH CH-OH Compound (8) CH; O

(13H (EH-OH CH CH-OH CH3 0 Compound (9) CH 0 (13H CH-OH CH CH-OH CH CHz 0 Compound (10) O (3H2 (EH-OH CH CH-OH CH3-(CHz)1o-CH:OCH7 0 Compound (11) CH-OH H-OH CHa-(CHz) s-C Hi-CE Compound (12) 0 g C I CH-OH x-( 2) u- 2 H (DH-OH Compound (13) The novel hardener of the present invention exhibits a good hardening effect without any undesirable effects on the photographic properties, such as sensitivity, tone, storage stability and fog, of a photo-emulsion, even if added to a silver halide photo-emulsion. The novel hardener has the excellent characteristic that it quickly hardens gelatin after drying by virtue of its high activity. This quick hardening ability is especially important in the manufacture of photo-sensitive material of stabilized quality and free from post hardening.

The hardener of the present invention would not loose its hardening ability at all, even in the presence of other photographic additives. In addition, a gelatin-containing coating layer or gelatin-moldings whichhave been hardened in accordance with the present invention have the desirable characteristics that they have been improved to a great extent not only in water-resistivity but also in mechanical strength, such as scratch-resistivity compared with that before hardening. This is a particularly important advantage in the manufacture of various light-sensitive materials which are to be rapidly treated in an automatic photographic processing machine under conditions of high pH and high temperature, and those which should have a high scratch-resistivity withstanding the rapid treatment without any surface injury, and in the manufacture of cinematographic positive light-sensitive materials which are required to have a film surface of high mechanical strength withstanding repeated projections.

The novel hardener of the present invention may be synthesized by reacting 1,2-dihydroxyalkane derivatives with glyoxal, (a) under reduced pressure on a phosphorous pentoxide or other drying agent, as disclosed in the Journal of the Chemical Society, p. 1,036 (1955), or (b) with heating.

The synthesis of the hardener compounds of the present invention will now be illustrated by the following synthesis examples.

SYNTHESIS EXAMPLE I (Synthesis of Compound 1) A mixture of 55.3 g. of 3-chloro-1,2-propanediol and 72 g. of a 40% aqueous glyoxal solution was held in vacuo on phosphorus pentoxide until it was substantially solidified. The solidified material was added into a small volume of acetone and filtered to obtain 50 g. of white crystals. The crude crystal thus obtained was recrystallized from 50 ml. of isopropanol to obtain 72 g. of pure Compound (1) (melting point 97-99" C.).

Elementary analysis as C H C1O Calculated C: 35.61%, H: 5.34%. Found C: 35.76%, H: 5.47%.

SYNTHESIS EXAMPLE II (Synthesis of Compound (2)) 70 g. of pure Compound (2) (melting point 9697 C.) was obtained by utilizing a procedure as in the synthesis of Compound 1) except that 73 g. of 1,2-octanedio1 (boiling point 102 C./ 1.5 mm. Hg), prepared by oxidizing l-octane with performic acid was used in place of 3-chloro-l,2-propanediol, and ethanol was used as the solvent for recrystallization in place of isopropanol.

Elementary analysis as C H O' Calculated C: 58.82%, H: 9.80%. Found C: 58.70%, H: 10.01%.

SYNTHESIS EXAMPLE III (Synthesis of Compound (3)) A mixture of 50 g. of 3-n-butoxy-1,2-propanediol (prepared from 3-chloro-1,2-propanediol and sodium n-butoxide and having a boiling point of 138140 C./2.2 mm. Hg) and 50 g. of a 40% aqueous glyoxal solution was held in vacuo on phosphorous pentoxide for 4 days and then heated under reduced pressure (to C./5 10- mm. Hg) to eliminate volatile matter and, thereby, to obtain 45 g. of Compound (3) in the form of a colorless, syrupy, viscous liquid.

Elementary analysis as C H O Calculated C: 52.42%, H: 8.74. Found C: 52.15%, H: 8.91%.

SYNTHESIS EXAMPLE IV (Synthesis of Compound (4)) A mixture of 6.9 g. of 2-phenyl-1,2-ethanediol and 10 ml. of water was heated on a water bath and the aqueous solution thus formed was cooled to room temperature. The aqueous solution was added into 7.0 g. of a 40% aqueous glyoxal solution and heated at 50 C. for 2 hours. The solidified reaction product was washed with a small volume of acetone and there was obtained 7.2 g. of white crystal. The crude crystal was recrystallized from 50 ml. of ethanol to obtain 4.6 g. of pure Compound (4), having a melting point of 146.5 C.

Elementary analysis as C H O Calculated C: 61.22%, H: 6.12%. Found C: 61.12%, H: 5.90%.

SYNTHESIS EXAMPLE V (Synthesis of Compound (5)) A crude product (melting point 114-117 C.) of Compound (5) was obtained by repeating the procedure as in the synthesis of Compound (1), as mentioned above, except that 84 g. of 3-phenoxy-1,2-propanediol (prepared from 3-chloro-1,2-propanediol and sodium phenoxide and having a boiling point of -187 C./15 mm. Hg)

was used in place of 3-chloro-1,2-propanedio1. By recrystallizing from acetone, there was obtained 64 g. of white pure Compound (5), having a melting point of 125- 125.5 C.

Elementary analysis as C H O Calculated C: 58.41%, H: 6.19%. Found C: 58.40%, H: 6.13%.

SYNTHESIS EXAMPLE VI (Synthesis of Compound (6)) 23.2 g. of trans-1,2-cyclohexanediol was dissolved into 15 ml. of water and the resulting aqueous solution was mixed with 29 g. of a 40% aqueous glyoxal solution and held in vacuo on phosphorous pentoxide. After 3 days, the mixture was solidified and there was obtained a white crude product of a melting point 88-95 C. Byrecrystallization from 20 m1. of water, there was obtained 23 g. of pure Compound (6), having a melting point of 97- 100 C.

Elementary analysis as C H O Calculated C: 55.17%, H: 8.05%. Found C: 54.66%, H: 8.09%.

SYNTHESIS EXAMPLE VII (Synthesis of Compound (7)) 16.5 g. of the pure Compound (7) of a melting point 13 6 136.5 C. was obtained in the same manner as in the synthesis of Compound (6), as mentioned above, except that 22 g. of catechol was used in place of trans-1,2-cyclohexanediol.

Elementary analysis as C H O Calculated C: 57.14%, H: 4.76%. Found C: 57.03%,H: 4.68%.

SYNTHESIS EXAMPLE VIII (Synthesis of Compounds (8)-(13)) Compounds (8)-(l3) of this invention were also prepared by similar methods as previously described. The results are summarized in the following table.

HARDNERS (8)-(13), OBTAINED BY THE REACTION OF GLYOXAL AND TH 6 EXAMPLE 1 To separate aqueous gelatin solutions, each containing 80 g. of gelatin per kg. of solution, were added, respectively, a known hardener compound (mucochloric acid) and Compounds (1) and (7) of the present invention, in the amount shown in the following Table. The solutions were separately applied to a subbed cellulose triacetate film in such an amount as to provide a dry coating film of a thickness of 10 microns, and then the composite was dried to form specimens of coated film.

The thus-formed specimens were aged at room temperature for 1 day, 5 days or 14 days, or under accelerating conditions for 2 days, and thereafter the melting point of the gelatin film was determined in a 2% aqueous solution of Na CO H O whose temperature was rising at a rate of 1 C./min. On the other hand, the specimens aged under accelerating conditions were subjected in a dry state or after being soaked in a 2% aqueous solution of Na CO H O for 10 minutes, to a determination of scratch-resistivity. In the determination of scratchresitivity, there were used a needle having on its point end a diamond ball having a radius of 0.05 mm. for the dry specimen, and a needle having on its point end a stainless steel ball having a radius of 0.5 mm. for the soaked specimens. The needle was forced perpendicularly to the surface of the gelatin film and then moved in a direction parallel to the surface of the gelatin film at a speed of 5 mm./second. The load on the needle under which the gelatin film was injured was determined (hereinafter, the load under which the specimen of dry gelatin film was injured is referred to as the dry scratch-resisting strength; and the corresponding load to the specimen of gelatin film soaked in the aqueous alkaline solution is referred to as the wet scratch resisting strength).

E FOLLOWING 1 ,2- GLY C OLS Reaetant Purified products Analysis, percent Oom- Calcd. Found pound Yield, 1,2-glycols N0. M1. 0.) percent 0 H C H 2,3-butanedio1 (8) 70 48. 65 8. 11 48. 28 7. 85 2,3-pentanediol (9) 65 51. 85 8. 64 51. 38 8. 42 3-n-dodecyl-LZ-propanediol- (10) 80-82 33 64. 15 10. 69 63. 80 10. 81 1,2-dodecanediol (11) 104-104. 5 62 64. 62 10. 77 64. 38 10.71 1,2-octadecanediol (12) 90-90- 5 69. 77 11. 63 69. 99 11. 97 4-tei-t-butylcatechol (13) 114-116 51 64. 29 7. 14 64. 27 7. 38

l Syrupy liquid.

The hardener of the present invention may be used in any amount, though preferably, in an amount of from 0.1 to 10% by weight of gelatin. The hardener may consist of a single compound or of a mixture of two or more compounds and may be used either alone or in combination with known hardeners. The hardener may be used in the form of an aqueous solution or a solution in an organic solvent, such as an alcohol or a ketone. The photographic emulsion to which the hardener of the present invention is suitably added may be any silver halide, containing one or more halides, e.g., silver bromide, silver iodide, silver bromochloride, silver iodobromide, silver, chloro-iodo-bromide, and the like, and it may also contain chemical sensitizers, optical sensitizers, anti-foggants, coating aids, stabilizers, plasticizers, developing accelerators, toning agents, and like conventional additives.

The hardener of the present invention may be used not only in photographic light-sensitive materials but also for the hardening of gelatin-containing coating layers, such as those of a color filter and a baryta paper,- and, further, for the hardening of gelatin-containing moldings, such as gelatin capsules and gelatin sheets.

. The present invention will be further illustrated in more detail by the following examples.

The results obtained are summarized in the following Table.

Accelerated aging conditions (50 C., RH, 2 days) Dry: Wet 25 12 25 The above table indicates that the compounds of the present invention have a quick hardening elfect compared with the known hardener compound and give a hardened gelatin film having higher dry and Wet scratch-resisting strengths.

EXAMPLE 2 To separate photo-emulsions each containing 75 g. of gelatin and 60 g. of silver bromide per kg. of emulsion, were added in the amounts listed in the following Table, a known hardener compound (2,3-dihydroxy-1,4-dioxane) and Compounds (2), (4) and (6) of the present invention, respectively, and the emulsions were separately applied to a subbed cellulose triacetate film in such an amount as to provide a dry coating film of a thickness of 10 microns, and then dried to form specimens of dry films. The melting points of the emulsion films in a 2% aqueous solution of Na CO H O were measured on the specimens aged at room temperature of 3, 7 and 14 days; and the melting points of the emulsion films and dry scratch-resisting strengths were measured on the specimens aged under accelerated conditions for 2 days. On the specimens aged at room temperature for 30 days, the photographic properties were determined by developing at 20 C. for 10 minutes with a developer of the following formulation, and then fixing and washing with water.

G. N-methyl-p-aminophenol sulfate 1.0 Sodium sulfite (anhydrous) 75.0 Hydroquinone 9.0 Sodium carbonate monohydrate 30.0 Potassium bromide 5.0

Water to form a solution of 1 liter.

The results obtained are summarized in the following Table.

Room temperature for 3 7 14 days days days Specimen Amount Melting point number Compound (moi/kg.) C.)

None (control) 35 35 2,3-dihydroxy-1, 10 39 45 3x10 41 49 45 56 3X10 55 68 10- 47 60 3X10 58 75 10- 43 54 3x10 50 67 Accelerated aging conditions (50 0.,

80% RH, 2 days) Photographic properties y scratch- Rela- Melting resisting tive point strength sensi- Specimen number G.) (g.) tivity 'y Fog;

As indicated by the above Table, the specimens containing the compounds of the present invention (Specimens No. 4 to 9) exhibited a quick hardening and a high scratchresisting strength, compared with the control specimen (Specimen No. 1) and those having a known hardener compound (Specimens Nos. 2 and 3). Further, the compounds of the present invention had little undesirable efiects on the photographic properties.

8 EXAMPLE 3 To separate photographic emulsions, each containing 75 g. of gelatin and 62 g. of silver iodobromide, were added known hardener compounds (formaldehyde and mucochloric acid), and Compounds (3), (5), and (6) of the present invention, in the amounts listed in the following Table, respectively, and the emulsions were applied separately to a subbed cellulose triacetate film in such an amount as to provide a dry coating film of a thickness of 10 microns and then dried to form specimens.

The melting points of the emulsion films in a 2% aqueous solution of Na CO H O were measured on the speci mens aged at room temperature for 3, 7 and 14 days, respectively, and the melting points and scratch-resisting strengths were measured on the specimens aged under accelerating conditions.

The photographic properties were determined on the specimens aged at room temperature for 30 days by developing at 20 C. for 10 minutes using a developer as in Example 2, and then fixing and washing with water.

The results obtained are summarized in the following Table.

Room temperature forp d 3 d 7 d 14 ays ays ays Specimen Amount number Compound (moi/kg.) Melting point C.)

1 None (control) 0 35 35 35 2 Formaldehyde 2X10- 37 39 46 3 do; 4X10- 38 42 52 4 Mucochloric acid 2 10- 37 38 40 5.-- 39 42 45 6 Compound (3) 48 63 66 7.. -do.. 65 76 79 8. Compound (5) 42 65 68 9--- -do 10- 57 73 74 10 Compound (6) 2X 10- 45 62 63 11 o 4X 10-- 60 74 77 Accelerated 'ng conditions (5% C.

80 RE, 2 days) Photographic properties Scratch-resisting strength (g.) Relative Melting sensipoint 0.) Dry Wet tivity 7 Fog As indicated by the above Table, the specimens which contain the compounds of the present invention (Specimens Nos. 6-11) exhibited a quick hardening effect and a high scratch-resisting strength when compared with the control specimens (Specimen No. 1) and those containing the known hardener compounds (Specimen Nos. 2- 5). Further, the compounds of the present invention had little undesirable effect on the photographic properties.

EXAMPLE 4 An aqueous gelatin solution containing 80 g. of gelatin per kg. of solution was uniformly applied to a subbed cellulose triacetate film base in such an amount as to provide a dry coating film of a thickness of 10 microns and then dried to form specimens. The specimen thus obtained was soaked for 1 minute in an aqueous solution containing 5 g. of Compound (1) of the present invention per 1 liter of solution, and then the melting point and dry and wet scratch resisting strengths of the gelatin film were determined. The melting point and wet scratch resisting strength were measured in a 2% aqueous solution of Na CO H O after soaking the specimen in the aqueous solution as mentioned above, and without drying it. The

dry scratch-resisting g tl i 'a'sl'rneasured after soaking the specimen as-nienti-oned'ab e=- anddrying it at room temperature .I ie results o tain. (1 are m ed i the following Table.

Scratch resisting 5; dldeltihg g strength (g.)

a t n Compound 0.) Dry Wei: 1 I

None (control) 35 25 13 Compound (1) 8O 38 42 As indicated by the above Table, the specimen which has been treated with an aqueous solution containing the compound of the present invention exhibited a high melting point and a high scratch resisting strength compared with the specimen which had been treated with an aqueous solution not containing such a compound.

What is claimed is:

1. A process for hardening gelatin which comprises reacting the gelatin with a hardening amount of at least one compound represented by the formulae:

4 CHKCHzh-C I CH-OH H-OH 0 and (Jr Ii \CHOH CHt(CH )I4CH2H CH-OH 3. The process of claim 2, wherein said compound is 0 HQC/ CH0H (3H (JR-0H CH3(CH2)4C2 0 4. The process of claim 2, wherein said compound is cmwmn-cm-o-om- H 5. The process of claim 2, wherein said compound is CH: 0 C cfi \CH-OH hm H ('JH-OH C r O 6. The process of claim 2, wherein said compound is \CHOH H-OH CH-OH CH- OH H-OH o C \CHOH ('JH CHOH CHa-(CHQlTCHz-O-Cfl 0 10. The process of claim 2, wherein said compound is oh, \CH-OH CH;-(0H1) -CH -CH CH-OH 11. The process of claim 2, wherein said compound is 2,870,013 1/1959' 'letrre s flr nan;A; 96-4-1100 References Cited UNITED. STATES 'PATEN rs 1 fl 5 HOWARD E. SCHAIN, Primary Examiner 

